Creating the "ray of light" effect

hey I’m new to flash and I’m trying to create the “ray of light” effect found here:

On page 4 where you fill the shape of the light, i cant get the fill to work. I’ve filled normal shapes just fine, but I can’t figure out how to fill that shape with 3 lines (i’m guessing because it’s not a shape?) anyway I made the letter a symbol, i put it as a video clip. Anyone know what I’m doing wrong?